In the Light of day the orb reveals five runes upon the ground.  The runic projections represent the Five Virtues of the Light  and the wisdom that each Virtue holds in the fight against heresy.

In the darkness of night, the Light of the moon reveals a different set of runic symbols.  These symbols are believed to be the Five Truths about mortality and heresy that Caormastus philosophized about.  It is from these Five Truths that the Five Virtues were revealed to Caormastus by the Light. These Truths are later enumerated and expounded upon by Genhein the Wise in his Book of Wisdom.
These Truths were communicated to Saint Caormastus in a similar manner to when the Church of the Holy Light was formed, and Mereldar had her visions of five forms, humming and glowing with holy power. But, she mistook them, and interpreted them imperfectly. Saint Caormastus also experienced revelations that brought him to enumerate the Five Truths and the Five Virtues … which were later put down in various writings which came to be known as the “Pious Pages” , and selections of those eventually became the Codexus Caelesteum.

The orb itself is a creamy, pearlescent white sphere of an unknown material, though it has some qualities and appearance to be of crystal.